Over the past 30 years, the principles of oncology treatment have evolved from a single surgical approach to a multidisciplinary approach. With the continuous subdivision of specialties and formation of subspecialties, the boundaries of disciplines have become more and more blurred. Therefore, communication and collaboration among various disciplines are becoming more and more important, and the multidisciplinary team (MDT) model of diagnosis and treatment has emerged. At present, MDT has become an important part of the clinical process in NCCN clinical practice guidelines for oncology. Gastrointestinal stromal turnor (GIST) is the most common gastrointestinal tract mesenchymal-derived tumors. Its pathogenesis, diagnostic tools, pathological immunohistochemistry, genetic testing and targeted therapy are more complex and specialized than other GI tumors, therefore, MDT model is more important and necessary in the diagnosis and treatment of GIST. The workflow of MDT is usually that patients are referred to the appropriate MDT team after the first doctor’s consultation, and the MDT team performs relevant imaging or laboratory examinations and special examinations according to the characteristics of the disease, and then formulates a treatment plan according to the clinical treatment guidelines or I clinical research protocols, taking into account the individual conditions of the patients. The advantages of this working model are that the doctors in each specialty in the MDT are experts in subspecialty research, their research in a particular direction of the disease can follow the latest international research progress, and their diagnosis and treatment level is at the highest level among their peers. After multidisciplinary consultation and discussion, the MDT can make the best treatment plan for a specific patient according to the commonly accepted treatment principles and clinical guidelines. Through specific case consultation and discussion, MDT further promotes the communication between different disciplines and enhances the understanding of different disciplines so that doctors or patients of different specialties have a more comprehensive knowledge of oncology and ensure the implementation of the best treatment plan. Based on the characteristics of GIST treatment strategy, the multidisciplinary team of GIST usually includes: gastrointestinal surgeons, gastrointestinal endoscopists, pathologists, diagnostic radiologists, basic oncology researchers and nurses or sometimes social workers and patients. The most important form in the development of the MDT treatment model is the regular, scheduled MDT meeting, which is a routine, periodic consultation discussion in which multidisciplinary specialists attend together. The following basic work elements should be accomplished: clarifying the diagnosis, establishing the treatment process, establishing clinical decisions and evaluating the results of decision implementation to obtain feedback. In this process, it is important to organize the meeting effectively and to complete the above tasks successfully through the meeting, so a competent organizer is needed. Given that surgical treatment remains by far the most important part of GIST treatment. Therefore, a surgical specialist should generally take the lead in organizing the multidisciplinary team. Since the treatment of GIST is highly specialized, especially in primary hospitals, it is often difficult to master, so it should be advocated in general hospitals with certain strengths, so that the treatment and prognosis of patients tend to be more standardized and beneficial. MDT in GIsT preoperative application All patients suspected of GIST should undergo rigorous and comprehensive imaging examinations, including endoscopy, ultrasound endoscopy, cT and MRI, before receiving surgical treatment. Endoscopic techniques allow direct visualization of intraluminal lesions in the GI tract and are the most commonly used diagnostic tool for GI diseases and the initial means of obtaining a diagnosis for most GISTs. However. Since GIST is a tumor located in the submucosa and covered by normal mucosa, normal biopsy often cannot obtain tumor tissue, therefore, further diagnosis often requires ultrasound endoscopy. Ultrasound endoscopy can determine the location of the tumor in the wall of the digestive tract and the image of adjacent tissues outside the lumen more accurately. For an elevated lesion with normal gastrointestinal mucosa, ultrasound endoscopy can distinguish whether the lesion is intramural or extrinsically compressed, and for intramural lesions, it can help determine whether the lesion is substantial or cystic, which is of great value for the diagnosis of submucosal disease. Enhanced abdominal cT or MRI can clearly show the location of the lesion and its relationship with adjacent organs, and can exclude metastatic lesions in distant organs, which is important for determining the resectability of the tumor. All patients to be diagnosed with GIST should preferably be evaluated by a multidisciplinary team before surgery. The purpose of preoperative MDT meeting is as follows. 1. To obtain a relatively clear preoperative diagnosis: Unlike tumors of epithelial origin in the gastrointestinal tract, it is more difficult to obtain a clear pathological diagnosis before surgery for GIST. However, GIST has certain characteristic endoscopic and imaging manifestations, and most GIsT cases can be diagnosed preoperatively by experienced gastrointestinal endoscopists and radiologists and surgeons. 2. Exclusion of cases without surgical indications: For some GISTs with small diameters, the indications for surgery should be discussed and standardized through MDT to avoid overtreatment. Although the literature suggests that GISTs are potentially malignant, not all GISTs require surgery, and some GISTs may not require treatment for life, so this is particularly important. GISTs larger than 2 cm in diameter, especially in non-gastric sites, should be treated aggressively with surgery. Preoperative evaluation of the primary tumor site and distant organs can exclude some cases of systemic progression, and the benefit of targeted therapy in these cases is significantly higher than that of palliative surgery. In addition, the author’s experience is that. Preoperative MDT discussion can minimize the occurrence of misdiagnosis and mistreatment in some patients. For some patients with suspected gastric GIST lesions that appear as submucosal bulges on endoscopy, ultrasound endoscopy sometimes cannot accurately determine the level of origin of the lesion. The MDT team of the author has excluded one case of submucosal bulging lesion due to compression of the gastric antrum by the inferior pole of the spleen and one case of compression of the gastric antrum by a large cyst in the left lobe of the liver through preoperative case discussion, thus avoiding unnecessary surgery and possible concomitant medical risks.3. Assessment of surgical resectability and development of surgical plan: The extent of surgical resection for GIST should depend on the tumor site. In general, the principle of non-expansion surgery should be followed. The current consensus is that wedge resection for gastric GIST is effective in ensuring tumor-free margins and minimizing complications, and that patients do not benefit from expanded resection. Partial or total gastrectomy should be performed only when the tumor is too large to be wedge resected or involves the pylorus or gastroesophageal junction. Wedge resection of the esophagus, duodenum, colon and rectum should also be pursued, or if technically infeasible, resection of the intestinal (tube) segment. If necessary, pancreaticoduodenectomy or combined transabdominal perineal resection should be performed, and care should be taken to prevent tumor rupture during surgery. The use of laparoscopic resection in the treatment of GIST has become more and more widespread in recent years, and the current NCCN guidelines suggest that laparoscopic resection is acceptable for tumors 5 cnl or less in diameter. Tumors larger than 5 cm in diameter have also been reported to be resected by hand-assisted laparoscopy. However, laparoscopic or hand-assisted laparoscopy for GIST should be performed by a laparoscopically experienced surgeon after MDT discussion and with strict reference to the non-rupture and non-contact principles of open surgery, taking care to protect the incision from implantation, and if necessary, promptly reversing the open procedure. The use of endoscopic resection in the treatment of gastric GIST is still controversial. The focus of the controversy is on the radicality of the tumor and surgical safety. The author’s unit has successfully performed nearly 50 cases of combined endoscopic and laparoscopic surgery for GIsT, and the author’s experience is that combined endoscopic treatment can better compensate for the shortcomings of endoscopic treatment alone in the above two aspects in appropriate cases, and the postoperative recovery has obvious advantages over traditional open surgery. However, since there are still controversies, dual-scope treatment must be evaluated through a rigorous MDT discussion and performed by experienced endoscopic and laparoscopic specialists. 4. Assessment of comorbidities and surgical risks: With the aging of the population, there is a tendency to increase the number of surgical patients with medical comorbidities. Through MDT meeting, we can assess the patient’s ability to tolerate the surgery, and for some GIST patients with comorbidities, we can minimize the incidence of postoperative complications by perfecting the preoperative preparation as much as possible. For some patients with large tumors. In some cases where combined organ resection may be required, preoperative preparation can be done to minimize the impact of surgery on the patient’s organism. For some cases with progressive disease and some cases with tumors located in the esophagus, cardia, duodenum or rectum, targeted therapy can be used to achieve tumor shrinkage and maximize surgical resectability and achieve the purpose of organ preservation. However, clear pathological evidence needs to be obtained before targeted therapy, which requires endoscopic ultrasound-guided fine-needle aspiration biopsy by an experienced endoscopist at an eligible center. This group of patients will be evaluated and selected for individualized treatment through MDT. It will greatly improve their prognosis and quality of life. The author had admitted a 28-year-old patient with low rectal GIST and an 82-year-old patient with giant retroperitoneal GIST. Through MDT meeting, a detailed diagnosis, preoperative neoadjuvant therapy, reduction surgery and postoperative adjuvant therapy were developed, and the surgery was successfully performed to avoid the physical and psychological harm caused by stoma and the surgical risk caused by combined organ resection. The significance of MDT in postoperative follow-up of GIST The biological behavior of GIST is diverse and high-risk patients have a high possibility of postoperative recurrence and metastasis, so all GIST patients need to undergo MDT expert discussion to decide further treatment after pathological confirmation and genotyping after surgery. The purpose of postoperative MDT discussion is as follows. In 2002, Fletcher et al. proposed the NIH-NCI criteria, which for the first time clarified the malignant risk classification of GIST based on tumor size and nuclear fission number. In 2005, Miettinen et al. found that tumor site was significantly correlated with prognosis in a controlled multicenter study with a large sample. Therefore, in 2006, Miettinen reported that the GIST malignancy risk grading criteria added tumor site as a factor to the NIH and NCI criteria. In 2008, JoensIIU et al. proposed a modified NIH malignancy risk classification. The effect of tumor rupture on prognosis was added to the previous one. With the continuous updating and rationalization of the prognostic criteria, the clinic can more accurately determine the prognosis of GIST patients. In China, after a long-term study on a large sample size of GIST, Hou Yingyong et al. screened out 12 morphological indicators to determine the malignancy of GIST, including visual dissemination (liver metastasis, abdominal dissemination), microscopic dissemination (lymph node metastasis, vascular infiltration, fatty infiltration, mucosal infiltration and nerve infiltration) and morphological indicators in situ (myxomatous infiltration and nuclear schizophrenia greater than or equal to 10/50 HPF), and GIST pathologists in the MDT panel play a large role in the postoperative risk assessment. The author’s experience is that oncologic pathologists specializing in GIST pathology can provide more standard nuclear splitting image detection rate and can determine the prognosis of GIST patients more accurately in combination with other indicators (such as tumor necrosis, infiltration and heterotypes). 2, grasp the appropriate adjuvant treatment indications: GIST patients who receive complete resection, 5-year survival rate of up to 48%. 65%, but 30% to 45% of patients will recur. In 2007, the results of a phase III clinical double-blind controlled study (Z9001) by ACOSOG directly led to FDA approval of imatinib as an adjuvant for patients with resectable GIST. Therefore, patients with intermediate or high risk GIST should receive conventional imatinib adjuvant therapy after surgery, but the optimal duration of adjuvant therapy has not been determined. NCCN 2009 recommends that patients with intermediate risk classification should receive 1 year of adjuvant imatinib therapy: while patients with high risk classification should receive longer treatment: the domestic consensus recommends that patients with high risk classification should receive at least 2 years of treatment. Patients with different genotypes of GIST have different responses to imatinib treatment. It has been found that the response rate of conventional dose of imatinib, c-kit exon 11 is greater than exon 9 and then greater than wild type, while studies have confirmed that GIST patients with c-kit exon 9 respond better to high dose (800 mg/d) imatinib treatment than conventional dose. Therefore, it is an important task for the MDT team in GIST to select appropriate adjuvant cases, perform the necessary genetic testing and choose the appropriate dose through MDT discussions. For a small number of specific mutation types of GIST, genotype determination can also avoid ineffective adjuvant therapy. It can reduce the pain of patients and avoid wasting medical resources. For example, the author once admitted a case of gastric giant GIST, the postoperative genotype was determined as PDGFRA D842V, which showed primary resistance to imatinib, so no adjuvant therapy was performed after surgery, and close follow-up has been performed. 3. Standardized postoperative follow-up assessment: GIST has a certain rate of recurrence and metastasis after surgery, generally manifesting as recurrence of tumor bed or metastasis in the liver and peritoneal cavity. The postoperative follow-up mainly includes regular abdominal enhancement CT, endoscopy or PET and CT examination if necessary. The follow-up results should be reviewed by the MDT team, especially the oncologists, to determine whether there is tumor recurrence or metastasis. For cases with recurrence or metastasis, MDT discussion should be conducted to clarify: (1) whether it is consistent with the postoperative judgment of tumor biological behavior; (2) whether there are conditions and necessity for reoperation; (3) the selection or reselection of first-line and second-line targeted drugs and the adjustment of dose; (4) whether there are conditions and necessity for interventional treatment for some cases with liver metastasis. It is a patient-centered and multidisciplinary expert-based treatment model. Practice has proven that the MDT model is a working organization and method that can improve the efficacy and guarantee the level of diagnosis and treatment.